Method of preparing apples for cold packing



Patented June 1l, '1935 UNITED STATES PATENT OFFICE James S. Tierney,Upper Darby, Pa. No Drawing. Application August 1. 1934,

Serial No.

2Claims.

'Ihis invention relates to a method of preparing apples for coldpacking, and more particularly to the preparation of fresh apples forfreezing in such manner as to retain the true flavor, color, texture,and rmness of the fruit. A

Heretofore it has been proposed to treat apples in preparation forfreezing with brine or a solution strongly impregnated with salt, andthus to prevent oxidization characterizes a fresh apple.

One of the principal objects of the present in` vention is to prepareapples for freezing in such manner as to prevent oxidization anddiscoloration, and at the same time to preserve the true iiavor and theoriginal firmness oi' the fruit.

Other more specific objectsl and advantages characteristic of myinvention will become more apparent from the description hereinafter setforth oi' one example of the practice thereof.

According to the preferred method, the fresh apples are first pared andcored, and then immersed in a weak salt solution, say a 2% solution ofsalt in water. 'I'he apples are then inspected andspecked, if necessary.After the apples are thus prepared, they are run through a slicingmachine and conveyed to a treatment tank where the pieces are immersedinto a solution of sugar, salt, lemon juice, and water. Desirably thissolution may include 0.5% of sugar, 5% of salt, and 0.5% of lemon juice.After the sliced apples have remained in this bath for about 21/2minutes, they are removed from the treatment tank and drained intoportable a solution having similar y .up of a higher percentageof sugarand lemon juice and a reduced amount f salt. Desirably this solution mayhave 20% of sugar, 11/2% of lemon juice and 1% of salt.

When the portable tanks are thus filled, they tanksv containing .areloaded into a vacuum retort and subjected to a relatively high vacuum,say 28 inches, and there held for a period of 45 minutes o thereabouts.At the end of this period the vacuum is broken, and the atmosphereallowed to enter the retort. The portable tanks are-then removed, andthe apples are drained and packed with sugar into. other containers. Assoon as these containers are iilled they are placed in a refrigerator.Desirably the temperature of the refrigerator is maintained atapproximately rero degree Fahr `'f.`':it until the apple pieces-arefrozen solid. he temperature is then raised to ingredients but madeabout 17 F., and held at this 'point until the fruit is ready for use. l

It will be noted that the weak salt solution into which the apples areoriginally placed when they come from the paring and coring machine isused for the purpose of preventing oxidization ofthe apples during theperiod of inspection and trimming,` and while they are passing throughthe slicing machine. 'I'he rst treatment tanks into which the applepieces are initially dropped from the slicing machine contain a solutionwhich is designed to prevent'discoloration, to retain the rmness ornatural texture, and to bring out the true apple avor. In this solutionthe salt ingredient assists the sugar in preservation and retardsoxidization, the sugar Aacts as a preservative, particularly preservingthe original firmness of the fruit, and the lemon juice, containingcitric acid, brings out the flavor. 'I'he nal solution in the portabletanks into which the apple pieces are drained from the initial treatmenttanks contains the same ingredients, but the quantities are changed,there being a greater amount of sugar and citric acid, and a -lesseramount of salt. The placing of the apples in the vacuum retort extractsair from the apple pieces, while they are held by a screen or the likebelow the level of the solution. When the vacuum is broken, the voids,caused by extraction with the solution by the pressure of the atmospherethereon, and the apple pieces become completely saturated with thesolution.

It will be particularly noted that forthe final immersion, instead ofemploying a solution containing a high percentage of salt, the saltingredient is negligible and only sucient to prevent oxidization. Thusthe sugar and citric acid serve, at vthis stage of the process, not onlyto preserve and bring out the ilavorof the fruit, but, as I have found,these ingredients serve also to counteract the strong salty taste whichmany apples have when they have been immersed for a. long period of timein a brine solution, or one in which the salt content issuillcientlyhigh to saturate the solution.

In other words, it is characteristic of this invention that theseveralingredients of the nal solution used in the vacuum retort, in'the combination herein described, functidn in their individualcapacities to preserve the fruit in the desired condition, andadditionally coact to maintain the original flavor of the fruit.

Having thus described my invention, I claim:

1. A method of preparing fresh apples for cold packing` which includesthe steps of immersing of the air, become filledy tion of salt. and

` the apple pieces in a solution containing a major portion oi sugar andcitric acid and a minor porwhile so immersed subjecting the pieces to avacuum, then breaking the vac- 5 umn, and packing and freezing thepieces.

2. A method oi preparing fresh apples for cold packing which includesthe steps of immersing the appie pieces in a solution of sugar, salt andmoo-1,35@

citric acid, then immersing the pieces in a' solution having a greateramount of sugar and citric acid and a lesser amount of salt, and whileso immersed subjecting the pieces to a vacuum, then breakingthe vacuum,and packing and freezing the pieces.

JAMES S. TIERNEY.

